Ghent University

output

19932026

researchers with a paper here

Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.

collaborating institutions

Showing 2020 · math.COShow all

15 papers · 2 filters

math.CO2020★ 5 cited

On exceptional Lie geometries

Anneleen De Schepper, Jeroen Schillewaert, Hendrik Van Maldeghem +1

Parapolar spaces are point-line geometries introduced as a geometric approach to (exceptional) algebraic groups. We characterize a wide class of Lie geometries as parapolar spaces…

math.CO2020

Graphs cospectral with NU $(n + 1, q^{2})$ , $n \neq = 3$

Ferdinand Ihringer, Francesco Pavese, Valentino Smaldore

Let $H (n, q^{2})$ be a non-degenerate Hermitian variety of $P G (n, q^{2})$ , $n \geq 2$ . Let NU $(n + 1, q^{2})$ be the graph whose vertices are the points of $P G (n, q^{2}) ∖ H (n, q^{2})$ …

math.CO2020★ 1 cited

Switching for Small Strongly Regular Graphs

Ferdinand Ihringer

We provide an abundance of strongly regular graphs (SRGs) for certain parameters $(n, k, λ, μ)$ with $n < 100$ . For this we use Godsil-McKay (GM) switching with a partition of type…

math.CO2020★ 9 cited

Triangulations and Canonical Forms of Amplituhedra: a fiber-based approach beyond polytopes

Fatemeh Mohammadi, Leonid Monin, Matteo Parisi

Any totally positive $(k + m) \times n$ matrix induces a map $π_{+}$ from the positive Grassmannian $Gr_{+} (k, n)$ to the Grassmannian $Gr (k, k + m)$ , whose image is the amplituhe…

math.CO2020★ 11 cited

Constructing saturating sets in projective spaces using subgeometries

Lins Denaux

A $ϱ$ -saturating set of $PG (N, q)$ is a point set $S$ such that any point of $PG (N, q)$ lies in a subspace of dimension at most $ϱ$ spanned by poi…

math.CO2020★ 2 cited

Hamiltonian cycles and 1-factors in 5-regular graphs

Nico Van Cleemput, Carol T. Zamfirescu

It is proven that for any integer $g \geq 0$ and $k \in {0, \dots, 10}$ , there exist infinitely many 5-regular graphs of genus $g$ containing a 1-factorisation with exactly $k$ …

math.CO2020

Neumaier graphs with few eigenvalues

Aida Abiad, Bart De Bruyn, Jozefien D'haeseleer +1

A Neumaier graph is a non-complete edge-regular graph containing a regular clique. In this paper we give some sufficient and necessary conditions for a Neumaier graph to be strongl…

math.CO2020

Covers of generalized quadrangles, 2. Kantor-Knuth covers and embedded ovoids

J. A. Thas, K. Thas

In this paper, which is a sequel to \cite{part1}, we proceed with our study of covers and decomposition laws for geometries related to generalized quadrangles. In particular, we ob…

math.CO2020★ 2 cited

On the chromatic number of two generalized Kneser graphs

Jozefien D'haeseleer, Klaus Metsch, Daniel Werner

We determine the chromatic number of some graphs of flags in buildings of type $A_{4}$ , namely of the Kneser graphs of flags of type ${2, 4}$ in the vector spaces $GF (q)^{5}$ for $q\g…

math.CO2020★ 7 cited

Small Weight Code Words of Projective Geometric Codes

Sam Adriaensen, Lins Denaux

We investigate small weight code words of the $p$ -ary linear code $C_{j, k} (n, q)$ generated by the incidence matrix of $k$ -spaces and $j$ -spaces of PG $(n, q)$ and its dual,…

math.CO2020★ 4 cited

Cameron-Liebler $k$ -sets in $AG (n, q)$

Jozefien D'haeseleer, Ferdinand Ihringer, Jonathan Mannaert +1

We study Cameron-Liebler $k$ -sets in the affine geometry, so sets of $k$ -spaces in $AG (n, q)$ . This generalizes research on Cameron-Liebler $k$ -sets in the projective geomet…

math.CO2020★ 8 cited

Cameron-Liebler line classes in AG(3,q)

Jozefien D'haeseleer, Jonathan Mannaert, Leo Storme +1

The study of Cameron-Liebler line classes in PG( $3, q$ ) arose from classifying specific collineation subgroups of PG( $3, q$ ). Recently, these line classes were considered in new sett…

math.CO2020★ 6 cited

Veronese representation of projective Hjelmslev planes over some quadratic alternative algebras

Anneleen De Schepper, Hendrik Van Maldeghem

We geometrically characterise the Veronese representations of ring projective planes over algebras which are analogues of the dual numbers, giving rise to projective Hjelmslev plan…

math.CO2020★ 4 cited

Graphs, defined by Weyl distance or incidence, that determine a vector space

Anneleen De Schepper, Hendrik Van Maldeghem

We study to which extent the family of pairs of subspaces of a vector space related to each other via intersection properties determines the vector space. In another language, we s…

math.CO2020★ 8 cited

Split buildings of type F4 in buildings of type E6

Anneleen De Schepper, N. S. Narasimha Sastry, Hendrik Van Maldeghem

A symplectic polarity of a building Δ of type E6 is a polarity whose fixed point structure is a building of type F4 containing residues isomorphic to symplectic polar spaces (i.e.,…

On exceptional Lie geometries

Graphs cospectral with NU(n+1,q2), n=3

Switching for Small Strongly Regular Graphs

Triangulations and Canonical Forms of Amplituhedra: a fiber-based approach beyond polytopes

Constructing saturating sets in projective spaces using subgeometries

Hamiltonian cycles and 1-factors in 5-regular graphs

Neumaier graphs with few eigenvalues

Covers of generalized quadrangles, 2. Kantor-Knuth covers and embedded ovoids

On the chromatic number of two generalized Kneser graphs

Small Weight Code Words of Projective Geometric Codes

Cameron-Liebler k-sets in AG(n,q)

Cameron-Liebler line classes in AG(3,q)

Veronese representation of projective Hjelmslev planes over some quadratic alternative algebras

Graphs, defined by Weyl distance or incidence, that determine a vector space

Split buildings of type F4 in buildings of type E6

Graphs cospectral with NU $(n + 1, q^{2})$ , $n \neq = 3$

Cameron-Liebler $k$ -sets in $AG (n, q)$